With the advent of the importance of smoke detectors of the ionization type for homes or dwellings, many ionization smoke detection apparatuses are presently available which are either powered by a transformer connected to a conventional alternating current power source or a battery for providing a direct current power source.
Under certain conditions and in certain localities, there is a need for an ionization smoke detector device which can be extremely dependable even though there is a loss of alternating current power and which need not be supervised over long periods of time to insure that a battery is not dead and to insure that adequate signaling will alert the occupants of homes or dwellings of the presence of smoke. While it is recognized that rechargeable battery backup systems are used in many appliances and safety lights, the present invention is concerned with a use of such a rechargeable battery backup circuit in an ionization smoke detector apparatus.